The subject matter of the present invention relates to a method and apparatus responsive to a plurality of seismic data for generating a map illustrating data representative of a frequency shift of a plurality of seismic signals when said seismic signals propagate through a layer of fractured rock in an Earth formation.
Geologic formations containing fractures are an important source of hydrocarbon accumulations and an interesting target for geophysical exploration. The presence of fractures in a geologic formation will act as a high-cut filter with respect to the seismic wave that is propagating through the layer of fractured rock in the Earth formation. This produces a measurable and mappable change in the frequency spectra of the seismic signal propagating above the fractured zone compared to the frequency spectra of the seismic signal propagating below the fractured zone.